1)
Collect a cup of water from a local river, pond or stream. Observe its
color and any particles you can see in it.

2)
Take the stick or pencil and run it through the coffee filter so that it
can be suspended over the other cup.

3)
Slowly pour your water sample through the filter.What color is the water after it has been filtered?

4)
Use a magnifying glass to look at the particles left in the filer.What sorts of materials might have been in the water?

5) Make sure you
discard your filter and water samples when you are done!

Explanation:Even
under the best natural conditions, water is not completely pure.It contains bits of sand, dirt, salt, and tiny organisms.These must be filtered out before humans can safely use the water.However pollution often makes water so dirty that filtering is only the
first step in a complex purifying process.Water can be so polluted it is almost impossible to clean!

When
water isnít clean, it isnít only humans that are affected.Plants and animals can also become sick and die if their water supply is
polluted.Water pollution also
clogs up lakes and ponds, causes disease, and destroys the beauty of natural
areas.